The efficiency and the profitability of modern passenger aircraft dictate that the space that is available in the cabin be optimised when compared to aircraft models of the same class. The space available to each individual passenger has a direct influence on the comfort of passengers.
A further important efficiency factor with passenger aircraft is the payload provided by the respective aircraft. With a predefined takeoff weight of an aircraft, an increase in the payload can be achieved in particular if the so-called system mass and the so-called mass of expendable supplies are kept as low as possible.
In this context the term system mass relates to that mass that is required when a modern passenger aircraft is fitted out. This includes, for example, the mass of apparatus of a freshwater system or a service water system, air conditioning system and electrical equipment such as, for example, video recorders, monitors or audio systems. As far as the term “mass of expendable supplies” is concerned, in particular the mass of fuel carried on board is relevant.
Increases in the efficiency of modern aircraft engines, as well as improved aerodynamics in modern passenger aircraft, partly reflect the above-mentioned requirements. However, further improvements can only be achieved by way of a change in the aircraft architecture. This refers to a clever selection and arrangement of components that are required for fitting out the interior of an aircraft.